At first, in Clive James's new novel, which chronicles the rise of a Bombay street urchin into minor Bollywood film stardom, I was too aware of James as the sardonic outsider, the TV personality. It's as if he's delivering his wry travelogue commentary gazing at Bombay from his five-star Taj hotel room above the Gateway to India, or as he's speeding through the slums in an air-conditioned Ambassador car. Yet even then, I have to admit, James is funny and his observations, often, are right on target.

Here's James, for instance, on laundry: "Again, here is something that makes India marvellous: dirty water can give you clean clothes. In mainland China, by contrast, a thousand million people previously world-famous for their ability to do laundry are now, through the miracle wrought by communism, unable to wash your white shirt without turning it grey, or to press it without crushing the buttons like aspirin in a spoon."

James has a good feel for Bombay and not only because the hotel laundry doesn't pulverise his shirt buttons. He sympathises with this mega-city of "somnolent chaos and last-minute urgency", and he tries earnestly to pin down the proper vocabulary to describe the city's squalor without sensationalising or trivialising it. James' style has such a strong, humorous pull that, in the beginning, I thought it would flatten out his story with mockery. After a while, though, he stops intruding. Artfully, he slips off and leaves Sanjay, the street child gifted with good looks and cleverness, to pursue his obession: having sex with Mumtas, the reigning sex symbol of Bollywood whose "thundercloud hair was done in a strange, wonderful way that made it look wild and windblown and yet heavy, as if it had been rinsed in cream and then photographed while it was flying".

As a boy, Sanjay wanders out of his "rag-and-bone suburbette" of garbage and mud and climbs through a hole in the fence to the Silver Castle, a film studio outside Bombay. To Sanjay, it looked like "the place where the creation of Earth must have been planned, the fortress of the gods". He is fed, cleaned and coddled by a beautiful actress named Miranda. She quickly tires of Sanjay and discards him, but throughout his misadventures with the beggar gangs on the streets of Bombay, his memories of Silver City sustain him like a talisman.

Sanjay's first acting job is to flash his beautiful smile to help advertise a pavement tooth-puller. That's followed by a sojourn with a loquacious English pederast who likes slumming it and calling Sanjay after Kipling's Kim. The Englishman pays off Sanjay with some gay contacts among Bombay's very rich, and he gives him an English dictionary, which Sanjay uses to decipher stories in gossip magazines about his beloved Mumtas.

With a sly hand, James take digs at our own voyeurism of despair. Sanjay's big break comes helping western television crews do documentaries on Bombay's poverty. Eventually, an Australian crew comes to explore another obligatory Bombay topic - the Indian film industry- and they lap up Sanjay's gossip- magazine knowledge. He ends up back at the Silver Castle studio of his childhood and hustles a job as a junior stunt man. Horrible things happen to him.

From the Malabar Hills drawing rooms, where industrialists argue the merits of Lamborghini versus Ferrari, down to the gangs of beggar kids who smoke heroin before they curl up to sleep on top of the public urinals, James makes it all real.

As the India correspondent for this newspaper, I've come to know Bombay fairly well. I've probably been conned by the same pack of beggars outside the Gateway of India as James, and I've probably peered into the same brothels on Falkland Road as he did, and I think that James has captured the city right. He's a shrewd observer who takes in all of Bombay's complexities, its greed, its wretchedness and its dreams, without passing flip judgements. Often hilarious and always ironic, this is James's best novel. The next time I'm in Bombay, I'll be thinking of Sanjay.